The designated hitter is one of the most important and most debated roles in baseball. The DH bats in place of the pitcher, letting teams keep a dangerous hitter in the lineup instead of sending a weak-hitting pitcher to the plate.
But here is what trips up a lot of fans: the DH rule is not the same at every level of baseball. What is allowed in Major League Baseball differs in key ways from college and high school. So how does the designated hitter rule actually work, and how does it change as you move from the pros to the amateur game?
The MLB version became universal only recently, while college and high school have their own twists that actually offer more flexibility than the pros in one important way. Understanding the differences clears up a lot of confusion.
The chart below breaks down the DH rule at all three levels: MLB, college, and high school. Take a look, then we’ll explain each one in detail.
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What Is the Designated Hitter?
The designated hitter, or DH, is a player who bats in place of the pitcher but does not take the field on defense. The idea is simple: pitchers are generally weak hitters, often an easy out, so the DH lets a team put a stronger bat in that lineup spot instead. Importantly, the DH does not add a tenth hitter to the lineup.
A team still has nine batters in the order; the DH simply occupies the spot that would otherwise belong to the pitcher. The role is usually given to a powerful hitter who may no longer be suited to play the field every day, or used to give a regular position player a partial rest day while keeping his bat in the lineup.
The DH Rule in MLB
Major League Baseball first introduced the designated hitter in 1973, but only in the American League. For nearly 50 years, this created a fundamental split: AL teams used a DH, while in the National League pitchers had to bat for themselves.
That difference shaped strategy, especially in interleague play and the World Series. After a one-year trial during the pandemic-shortened 2020 season, MLB made the DH universal starting in 2022, applying it to both leagues permanently.
Today every MLB team uses a DH. The league also added a “two-way player” provision, often called the Ohtani rule, which lets a player serve as both the starting pitcher and the DH, so that when he is removed from the mound he can stay in the game as a hitter.
The DH Rule in College Baseball
College baseball, governed by the NCAA, also uses a designated hitter, and like MLB the DH must bat for the pitcher. But college baseball actually pioneered the two-way concept long before the pros.
Under NCAA rules, if a pitcher is also a good hitter, the coach can let him bat for himself, in which case he is treated as two separate players on the lineup card: a pitcher and a designated hitter, abbreviated P/DH.
This means the pitcher can be removed from the mound but stay in the game as the DH, or be replaced as a hitter while continuing to pitch. It is essentially the same idea MLB later adopted for Shohei Ohtani, and it gives college coaches valuable flexibility with their best athletes.
The DH Rule in High School Baseball
High school baseball, governed by the NFHS, has the most flexible designated hitter rule of all, and it is the one that most surprises fans. The traditional option works like the pros: a DH is listed as a tenth starter who hits for one of the nine defensive players.
But here is the key difference: in high school, the DH does not have to bat for the pitcher. He can be designated to hit for any one of the nine starters. On top of that, a rule change in 2020 added a “Player/DH” option, allowing any starting defensive player, including the pitcher, to serve as his own DH. That gives high school coaches three different lineup structures to choose from, more options than either college or the pros.
Why the Rule Causes Confusion
Most of the confusion around the DH comes from assuming it works the same everywhere, when it does not. The single biggest difference is who the DH can replace: in MLB and college, the DH must bat for the pitcher, but in high school he can bat for any starter.
The other tricky area is the two-way player. All three levels now allow a pitcher to also be the DH, but the exact substitution rules differ, and once certain substitutions happen, the two-way role can be terminated for the rest of the game. For everyday fans, the simplest way to keep it straight is this: the higher the level, the more the DH is tied specifically to the pitcher. If you enjoy these rule breakdowns, see our explainer on the dropped third strike rule.
The Bottom Line
The designated hitter rule lets a team replace its pitcher’s weak bat with a stronger hitter, and while the core idea is the same everywhere, the details change by level. MLB made the DH universal in 2022 and ties it to the pitcher, college does the same while pioneering the two-way P/DH, and high school is the most flexible, letting the DH bat for any starter. Whether you love the extra offense or miss the old-school strategy of pitchers hitting, the DH is now a permanent and central part of baseball at every level.